1. Field of the Invention
The present invention relates to an encoder scale and a manufacturing and attaching method thereof, and more particularly, to an encoder scale that can stably resolve a phenomenon in which the encoder scale is charged with static electricity and a manufacturing and attaching method thereof.
2. Description of the Related Art
In the related art, as described in JP-A-2004-333417, for example, an electromagnetic induction type (magnetic) linear encoder has been used. In the electromagnetic induction type linear encoder, scale coils (conductive pattern layers) are formed in a measurement direction of the encoder scale. Particularly, a ground pattern is formed outside the scale coils to ground the ground pattern to a scale base. Accordingly, static electricity generated in the encoder scale is let to go to the scale base.
However, the electromagnetic induction type linear encoder described in JP-A-2004-333417 basically serves as an effective countermeasure against static electricity for a part of the encoder scale in which the ground pattern (which may be a conductive pattern) is formed. That is, such a ground pattern may not be sufficiently effective for a part other than the part in which the ground pattern is formed.
For example, when the scale coil itself is charged with static electricity, operation failure, malfunction, or the like of the electromagnetic linear encoder may be caused in discharging the static electricity accumulated in the scale coils.